Do any of you guys get a steady stumble at a red light after you fill your tank? But the next morning the car is fine and throughout the rest of the tank?
Thanks !

 

My car has done this occassionally when just started cold with a recent full tank. Not sure why wanted to replace my fuel filter to find out there isn't one to replace unless you want take the fp out.

 

just to be sure, you don't leave your car running when filling up do you?

 

This happened to me as well as a CEL code. Agreed!!!!!


STevo

 

I have had similar issues on my evo with the motor stumbling. It was pretty random, and would not do it for days at a time. Once in a while the car would also stall while in idle.

My problem was solved by replacing the IAC on the trottlebody.

 

I have this issue after every fill-up. It only last for the first few minutes of driving and only at a stop like you have stated. Not sure if I need to drain the tank and try to get out some possible dirt/contamination, or if there is another solution.

 

Never on stock ROM, and several maps afterwards, never. Stumbles sound like plugs to me, or a idle map problem. The amount of fuel in the tank shouldn't effect idle?

 

^^^I just wonder if filling up the tank may cause small debris to become suspended in the tank...causing the stumbling. The car idles perfectly any other time, and like the OP said, after running the car for a little while. It's only during the first few minutes after fill-up.

 

What happens if you do leave the car runing while filling up?? i always shut it down but now curious.

 

I would check the fuel filter if you think it is gas/debris related, but the filter should be doing its job. The fact that the idle is the only issue leads me to believe that you have a problem with the IAC.

One way to check your IAC is to remove it from the throttle body. You can do it without removing the whole assembly. It has 3 screws, but I would use a socket as a screw driver may result in stripped screws.

Once it is removed, plug it into the harness. You will need someone to turn the key to the on position without starting the car. This will send current to the IAC, and if the value does not move out it is time to replace. This device is what the ECU uses to modulate idle.

The only other way to modify the idle is to change the map with flashing software, or adjust the idle screw on the throttlebody. Good luck sorting out this issue.

 

if you fill the tank to the brim it will stumble because the system is designed to work with air up top.
Mine has done it before. just dont top the tank off

 

Thanks kwanza and scott yo. I need to fill up today. So, I will stop a little short of full and see what the results are. Will report in later.

 

My car does the same thing, after every fill up my car will kinda hick up for a couple of minutes at a stop and then will work perfectly fine. Let me know whats wrong! lol

 

Just an update. After filling my tank to about half, the idle still is a little flaky for the first couple of minutes.